Lebanese authorities say they have arrested a prominent Sunni Islamist cleric wanted in connection with a series of attacks on the country's army.

Officials said Sheikh Ahmed al-Assir was detained Saturday at the Beirut airport, adding that he was using a fake passport and appeared to have had surgery to change his appearance.

The volatile religious leader has been on the run since 2013, after the Lebanese army raided his compound in the southern port city of Sidon. At least 18 Lebanese soldiers were killed in the incident.

Al-Assir has helped fan sectarian tensions between Sunni and Shi'ite Muslims in Lebanon and is a fierce opponent of Hezbollah. He accuses the Lebanese government of working with the Shi'ite armed group, which is fighting on the side of President Bashar al-Assad in the Syrian civil war.

The Lebanese government has accused al-Assir of forming an illegal armed group, among other charges. Several recent suicide bombings have been blamed on his followers.